Explosion-proof floodlight



April 27, 1965 1. Y.` MORRISON v 3,180,980

EXPLOSION-PROOF FLOODLIGHT Filed NOV. 28, 1962 WIIWEIMW l llllllllm INVENTQR /an You/79' Marr/son Q M d-m W, @WW

ATTORNEYS United States Patent 3,180,980 EXPLSION-PROOF FLOODLIGHT Ian Y. Morrison, Clarkson, Ontario, Canada, assignor to The Pyle-National Company, Chicago, Ill., a corporation of New Jersey Filed Nov. 28, 1962, Ser. No. 240,634 4 Claims. (Cl. 240-11.2)

This invention relates generally to electric light lixtures and'more particularly to an explosion-proof light fixture which can be used in a hazardous environment, The light fixture of this invention is rugged, can be easily serviced, has the lamp compartment isolated from the terminal block compartment with both compartments accessible from the lighting face of the fixture, has excellent heat transfer and dissipation properties, has an all threaded cover construction, is watertight and leakproof and is especially useful in locations having low head room.

The use of a quartz-iodine incandescent lamp as a source of light vis contemplated, although other light sources could be used Within the concept of this invention. i

It is, therefore, an object of the present invention to provide an explosion-proof, watertight light fixture especially adapted for use in locations having low head room.

Another object of the invention is to provide a light fixture having a completely threaded cover construction to eliminate bolts and facilitate maintenance.

Another Object of the invention is to provide a lamp compartment and a terminal block compartment having both compartments accessible from the lighting face of the fixture and sealed off and isolated from each other.

Another object of the invention is to provide a fixture having sealed wiring from a lamp to a terminal block separated from the lamp in explosion proof relation.

Yet another object of the invention is to provide means to easily unscrew the cover of the lamp compartment and the coverl of the terminal block compartment.

A further object of the invention is to provide a fixture having excellent heat transfer and heat dissipation properties.

Many other features, advantages, and additional objects will become manifest to those versed in the art from the detailed description of the invention which follows and the accompanying sheets of drawings in which a preferred embodiment of a light fixture incorporating the principles of the present invention is shown by way of illustrative example.

On the drawings:

having formed therein a lamp compartment 12 and a terminal block and wiring compartment 13. Y

The body portion 11 is essentially an elongated, rectangularly-shaped unitary structure and as can best be illustrated by a comparison of FIGURES 1 and 2, the depth of the body portion is relatively shallow in relation to its length and width thus providing fora minimal protrusion in operating environments requiring minimum head room. Thus the body 11 has parallel longitudinal walls 11 and 11 and parallel end walls-11c and 11d.

p ICC The body 11 is further'characterized by a at bottom wall 11e and a top wall 11,.

Internally of the body 11, there is formed a partition 11g which extends between the side walls 11c and 11d to partition the hollow interior of the body 11 into a major area forming the lamp compartment 12 and a minor area forming the block and wiring compartment 13.

Externally, the body is characterized by a centrally disposed boss or collar of generally circular configuration. A series of heat dissipation grooves l14 are formed in the latent face of the body portion. Each groove 14 begins at a point as at 14 lying in a circular path spaced radially outwardly of the boss 20 and extends longitudinally, opening through an end wall 11c or 11d as at 141,. The grooves 14 provide alternate iins 14., and recess areas for rapid dissipation of heat generated by the fixture by making more of the body portion surface accessible to the surrounding heat absorbing media, such as air, water or the like. The iixture itself, therefore, can be sized compactly and still form a radiation means having an enlarged diffusion area to remove Vsufficient heat to remain within tolerable heat dissipation limits.

Both end walls 11c and 11d of the body portion 11 have a pair of mounting holes 16 drilled and tapped therein. Since screws or other fastening means (not shown) can therefore be inserted vfrom the side of the xture for mounting purposes, it becomes unnecessary to provide means for mounting the fixture from the face of the body portion opposite the lighting face. A threaded opening for conduits as shown at 15 also opens to the end wall 11d of the body portion 11 and affords full ush mounting on the surface to which it is to be affixed. This is an important advantage when the fixture is to be installed in locations having limited head room.

Referring to FIGURE 1,-the lamp compartment 12 is located adjacent the terminal block compartment 13 and the covers of both compartments can be removed from the lighting face of the fixture to improve the serviceability of the fixture by making vall parts accessiblefrom the lighting face.

As best illustrated in FIGURE 3, the side of the body portion opening into the lamp and terminal block cornpartments is designated as the front side 17, and the side opposite the front side is designated as the back side 1S. Although the terms front side and back side are used, it is understood that the fixture of the present invention is equally adapted for mounting on a horizontal surface as well as a vertical surface or at any other angle. Generally, when a quartz-iodine lamp is used in the fixture, the lamp itself should be positioned within 4 of hori'- zontal to keep the iodine vaporized. The quartz-iodine lamp is an Vincandescent light source characterized by the provision of an envelope containing iodine which produces a restoring action on the filament resulting in a longer lamp life at a constant lamp output since no darkening of the lamp occurs.

Referring to FIGURE 3, a threaded port 19 connects the lamp compartment 12 and the terminalV block cornpartment 13 of the body portion 11. A raised boss or collar 20 extends from the body portion 11 and includes a threaded circular side wall 21 of the lamp compartment 12 land a threaded circular side Wall 22 of the terminal block compartment 13. The upper surface of the counter 20 forms a ilat shoulder23 around the lamp compartment and another shoulder 24 around the terminal block compartment.

In order to provide a light source, a quartz-iodine lamp 26 is mounted on the bracket 27 which is secured by screws as shown at 28 to the bottom Wall 29 of the body portion 11. 30 which, in the illustrated form of the invention, is

adsense The lamp 26 is positioned above a reecto'rV made of sheet form aluminum and is electro-chemically finisliedto form a reliective surface 30,l of permanently high reflectivity, although other types of reflectors can be used.

An annularly-shaped inner ring 31 having a threaded exterior side wall 32 is shown in mating engagement with the side wall 21 of the collar 20. A portion of the ring 31 extends above the shoulder 23 of the collar 20 and terminates in a fiat, radial surface 33 carrying a thin, annular gasket 34 on which rests a front glass lens 36. The glass lens 36 is circularly-shaped and in the preferred form is tempered heat and impact resisting plate glass having maximum mechanical and shock resisting characteristics as well as having high light transmission qualities. It is understood, of course, that different types of glass or other transparent or translucent materials could be used within the concept of the present invention.

Additional gasketing material surrounds the edge of the glass lens as at 37 as well as the marginal surface of the top of the glass lens as at 38. The cover 39 of the lamp compartment has an abutting surface 40 which engages the gasket 38 in sealing relation, and a threaded interior side wall 41 which is shown in mating engagement with the threaded upper portion of the inner ring 31. Thus, when the fixture is properly assembled the lower surface of the cover 39 will be in abutting engagement with the shoulder 23 of the collar 20. The cover surface 40 will sealingly engage the gasket 38, assuring a substantially leak-proof enclosure of the lamp compartment.

A terminal block 42 is mounted in the terminal block compartment 13. This terminal block forms a junction for an electrical conductor means 43, connected to the lamp 26, and electric power wiring means (not shown), connected to a suitable electrical source, can be inserted into the terminal block compartment through the threaded conduit feeding port 15. The terminal block is secured to the bottom wall 29 of the body portion 11 by means of mounting screws as shown at 46. A molded, externally threaded sealing plug 47 is shown surrounding and engaging the conductor means 43 in leak-proof and eX- plosion-proof relation and is threadedly inserted into the complementarily threaded port 19, thereby effectively isolating the lamp compartment 12 from the terminal block compartment 13. A cover cap 48 having an externally threaded depending flange 49 is shown yin threaded engagement with the side wall 22 so that an offset 50 of the cover cap is in sealing engagement with the shoulder Z4 of the collar 20, providing a leak-proof and explosionproof seal thereby.

When electric power conduit means is connected at the port 44 using leak-proof connector fittings (not shown) the entire terminal block compartment is leak-proof. The leak-proof capabilities of both the lamp compartment and the terminal block compartment are independent of each other because of the interconnecting sealing protection offered by the plug 47 and either compartment may be opened without interferring with the leak-proof capabilities of the other.

The cover 39 has transversely arranged tightening slots 51 formed therein for providing a means for effectively unscrewing and removing the cover 39 without the use of a large wrench. Any elongated instrument that will extend across the face of the cover 39 and fit into the slots 51 can be used to remove the cover 39. The cover cap 48 has a plurality of parallel spaced protuberances or bosses 52 which can be gripped by hand for removal of the cap 48. However, any tool that will fit between the bosses can effectively be used to provide additional leverage.

Although minor modifications of the present invention might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon all such modications as reasonably come within the scope of my contribution to the art.

l claim as my invention:

l. An explosion proof floodlight comprising an elongated shallow body portion having a front side and a back side,

a cylindrically-shaped large compartment formed in said body portion and opening to said front side,

said large compartment having a threaded side Wall,

an electric lamp mounted in said large compartment,

an annular inner ring having a flat marginal surface and having a top portion threaded complementarily to said side wall of said large compartment and threadedly secured thereto,

a substantially flat front glass shouldered on said marginal surface of said inner ring,

a centrally apertured cover having a flat marginal surface overlying said front glass and having a side wall threaded complementarily to said top portion of said inner ring and threadedly secured thereto,

a pair of thin tiat gaskets separating said front glass from said inner ring and said cover, respectively,

a cylindrically-shaped small compartment formed in said body portion adjacent said large compartment and opening to said front side,

a terminal block mounted in said small compartment,

a cover cap fixedly secured to said body portion covering said opening of said small compartment, and

electric circuit means connecting said lamp and said terminal block.

2. An explosion-proof floodlight comprising an elongated shallow body portion having a front side and a hack side,

a cylindrically-shaped large compartment formed in said body portion and opening to said front side,

said large compartment having a threaded side wall extending substantially perpendicularly to the plane of said front side,

an annular inner ring having a threaded outside wall in Vthreaded engagement with said side wall of said large compartment and having a iiat portion and a top portion,

gasket flat means overlying said flat portion of said inner ring,

a substantially flat circular front glass mounted on said gasket means, a second flat gasket means marginally overlying the periphery of said front glass,

a centrally apertured circular cover having a flat portion shouldered 0n said second gasket means and having a threaded inner side wall connected in threaded assembly to said top 'portion of said inner ring said cover having a plurality of transverse tightening slots formed therein,

an electric lamp mounted in said large compartment,

a cylindrically-shaped small compartment formed in said body portion and opening to said front side and 3, A compact explosion proof light fixture for use in hazardous and underwater locations comprising a relatively shallow elongated rectangularly-shaped body portion having a side wall and a bottom wall,

a lamp compartment formed in said body portion and opeiling to one side thereof opposite said bottom wa a lamp mounted in said lamp compartment,

means to secure said lamp to said bottom wall and insertable from said one side of said body portion,

means to cover said opening of said lamp compartment,

a terminal block compartment formed in said body portion adjacent said lamp compartment and opening to said one side of said body portion,

a terminal block mounted in said terminal block compartment,

means to secure said terminal block to said bottom Wall and insertable from said one side of said body portion, i

means to cover said opening of said terminal block compartment,

a threaded port formed in said body portion connecting said lamp compartment and said terminal block compartment, electric circuit means extending through said port connecting said lamp and said terminal block,

a threaded sealing plug threadedly inserted into said port and snugly engaging and surrounding said circuit means for effectively isolating said lamp cornpartment and said terminal block compartment, and

a conduit port extending through said side Wall into whereby said lamp can be affixed ilush with a mounting Y' surface Without interfering with the accessibility of said lamp and said terminal block and said securing means and said conduit port.

4. An explosion-proof floodlight comprising an elongated shallow body portion having a front side and a back side,

a cylindrically-shaped large compartment formed in said body portion and opening to said front side,

said large compartment having a threaded side Wall,

an electric lamp mounted in said large compartment,

an annular inner ring having a flat marginal surface and having a top 'portion threaded complementarily to said side wall ofsaid large compartment and threadedly secured thereto,

a substantially ilat front glass shouldered on said marginal surface of said inner ring,

a centrally apertured cover having a ilat marginal surface overlying said front glass and having a side Wall threaded complementarily to said top portion of said inner ring and threadedly secured thereto,

a pair of thin flat gaskets separating said front glass from said inner ring and said cover, respectively,

a. cylindrically-shaped small compartment formed in said body portion adjacent said large compartment and opening to said front side,

a terminal block mounted in said small compartment, a cover cap xedly secured to said body portion covering said opening of said small compartment,

electric circuit means connecting said lamp and said terminal block,

a port formed in said body portion connecting said large and said small compartments, and

a sealing plug in said port'for isolating said large and said small compartments from each other,

said electric circuit means extending through said plug between said lamp and said terminal block.

References Cited by the Examiner UNITED STATES PATENTS 1,258,827 3/18 Todd 24U-11.2 1,325,254 12/19 Legg 240-47 t 1,742,687 1/3() Burke 240-26 2,278,916 4/ 42 Critoph et al 2404-47 2,316,835 4/42 Blood 240-11-2 2,574,882 11/51 McDowell et al. 240-l1.2 2,849,574 8/58 Burns et al. 240-25 X 2,857,508 10/58 Klugman 24U-78 3,094,642 6/ 63 Duval S13-223 FOREIGN PATENTS 541,637 12/41 Great Britain.

NORTON ANSHER, Primary Examiner. 

1. AN EXPLOSION PROOF FLOODLIGHT COMPRISING AN ELONGATED SHALLOW BODY PORTION HAVING A FRONT SIDE AND A BACK SIDE, A CYLINDRICALLY-SHAPED LARGE COMPARTMENT FORMED IN SAID BODY PORTION AND OPENING TO SAID FRONT SIDE, SAID LARGE COMPARTMENT HAVING A THREADED SIDE WALL, AN ELECTRIC LAMP MOUNTED IN SAID LARGE COMPARTMENT, AN ANNULAR INNER RING HAVING A FLAT MARGINAL SURFACE AND HAVING A TOP PORTION THREADED COMPLEMENTARILY TO SAID SIDE WALL OF SAID LARGE COMPARTMENT AND THREADEDLY SECURED THERETO, A SUBSTANTIALLY FLAT FRONT GLASS SHOULDERED ON SAID MARGINAL SURFACE OF SAID INNER RING, A CENTRALLY APERTURED COVER HAVING A FLAT MARGINAL SURFACE OVERLYING SAID FRONT GLASS AND HAVING A SIDE WALL THREADED COMPLEMENTARILY TO SAID TOP PORTION OF SAID INNER RING AND THREADEDLY SECURED THERETO, A PAIR OF THIN FLAT GASKETS SEPARATING SAID FRONT GLASS FROM SAID INNER RING AND SAID COVER, RESPECTIVELY, A CYLINDRICALLY-SHAPED SMALL COMPARTMENT FROMED IN SAID BODY PORTION ADJACENT SAID LARGE COMPARTMENT AND OPENING TO SAID FRONT SIDE, A TERMINAL BLOCK MOUNTED IN SAID COMPARTMENT, A COVER CAP FIXEDLY SECURED TO SAID BODY PORTION COVERING SAID OPENING OF SAID SMALL COMPARTMENT, AND ELECTRIC CIRCUIT MEANS CONNECTING SAID LAMP AND SAID TERMINAL BLOCK. 